Mobile telephone fraud is the unauthorised use of a telecommunications network accomplished by deception via the wireless medium. This deception may take a number of forms which are generally classified under the broad headings of subscription fraud, theft and cloning.
Subscription fraud arises from the use of a false name and address when purchasing a mobile telephone and results in a direct loss to the service provider when a bill for usage of the telephone is unpaid.
Theft of a mobile telephone can lead to antenna misuse in the period between loss of the telephone and the reporting of that loss to the service provider. In some circumstances a mobile telephone may simply be borrowed by a fraudster who then steals air time. This particular type of theft may remain undetected for some time as it will become apparent only when the customer subsequently receives a bill.
The most serious fraud in a mobile system is that of mobile telephone cloning where the fraudster gains access to the network by emulating or copying the identification code of a genuine mobile telephone. This results in multiple occurrence of the telephone unit. The users of these clones may or may not be aware of this misuse. This fraud generally remains undetected until a customer becomes aware of unexpected items on a bill, by which time the total financial loss can be substantial.
Approaches to the problem of detecting mobile telephone fraud are described in specification No WO-A1-95/01707 and in specification No WO-A1-94/11959 both of which refer to techniques for building up an historical profile of subscriber activity so as to detect changes in that activity which may be indicative of fraudulent use.
Once illegal access has been gained to the mobile network, calls can be made at no cost to a fraudster, as either a genuine account holder is billed or the network provider is forced to write off the cost. It will be appreciated that once an identification code has been broken and a telephone has been cloned, this information can be disseminated to other fraudsters resulting in a high potential financial loss. The relatively slow response of conventional fraud detection procedures has become insufficient to address the rapid incidence of abuse of the system. It will also be appreciated that new forms of fraud are constantly coming to light and that these may not be immediately detectable by conventional techniques.
An object of the invention is to minimise or to overcome this disadvantage.
It is a further object of the invention to provide an improved apparatus and method for the detection of fraudulent use of a mobile telephone system.